Various types of mailboxes are known in the prior art. However, what has been needed is an impact resistant mailbox support apparatus including a mailbox support post and a mailbox having a dome-shaped body, a front door, and an attachment arm hingedly attached to the mailbox support post. What has been further needed is for the attachment arm to have at least one first spring-loaded self-returning hinge, such that the attachment arm of the mailbox is configured to selectively swing in one of a rightward direction and a leftward direction upon impact and return to an original pre-impact position following impact as a result of the at least one first spring-loaded self-returning hinge. Lastly, what has been needed is for the mailbox support post to optionally include a lower half, an upper half pivotally attached to the lower half, and a second spring-loaded self-returning hinge. The upper half is configured to selectively rotate in one of a rightward direction and a leftward direction upon impact and return to an original pre-impact position following impact as a result of the second spring-loaded self-returning hinge. The pivotable attachment of each of the mailbox support post and the attachment arm of the mailbox is structurally distinct from other mailboxes and better helps to prevent damage and destruction to a mailbox support post and a mailbox as a result of impact with a vehicle or a snowplow.